JPH0138667Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a crank handle device used for raising and lowering the floor of a bed, examination table, patient carrier, etc.

(Prior art) For example, in a bed, a desired portion of a floor section divided into a plurality of sections is rotated and raised to raise and lower, or a floor support frame that supports the floor section is raised and lowered horizontally.
A screw shaft type drive mechanism is widely used as a lifting mechanism for tilting, and an electric motor or a crank handle is used to drive the screw shaft. In order to prevent damage to mechanical components at the limit position of the mechanism or injury to the operator, such crank handles are designed so that they can be rotated idly when a torque exceeding a certain level is applied, and bent when not in use. It is preferable to make it functional. As such a crank handle device, there is a conventional crank handle device disclosed in, for example, Japanese Utility Model Publication No. 58-31546. This will be explained with reference to FIGS. 5a and 5b. This crank handle has a connecting rod b that is bendably fixed to the tip of a drive shaft a that is connected to a lifting mechanism for a floor such as a bed. A large-diameter insert c is provided at the end of the insert C, and the insert C is rotatably and slidably inserted into the drive cylinder d, and a compression spring is inserted between the insert c and the drive cylinder d. Interpose e,
The distal end f of the drive shaft a can be freely inserted into the drive cylinder d, and a contact part g with the distal end of the drive cylinder d is provided behind the distal end f, and these contact parts g and a chevron-shaped uneven portion h that engages with the drive cylinder d,
This is a configuration in which i is provided. In such a configuration, the driving cylinder d is moved in a direction away from the abutment part g against the repulsion of the compression spring e, and the tip part f is bent by making it outside the driving cylinder d, In addition, torque is transmitted from the drive cylinder d to the drive shaft a during the drive operation through the engaged chevron-shaped uneven portions h and i.
This is done by At this time, if a torque exceeding a predetermined value is applied, such as when the elevating mechanism reaches the limit position of elevating, the drive cylinder d will move as shown in FIG.
As shown in the figure, the uneven portions h and i are driven by the chevron-shaped inclined surfaces and move in a direction away from the contact portion g, and the uneven portions h and i are thus disengaged, allowing idling and generating excessive torque. This is something that can be prevented.

(Problem to be solved by the invention) In this way, when a torque exceeding a predetermined value is applied and the cylinder idles, the end of the drive cylinder d separates from the contact part g, and a gap j is formed therebetween. When the uneven parts h and i correspond again due to idling, the driving cylinder d rapidly moves toward the contact part g again due to the elasticity of the compression spring e, and the operation of eliminating the gap is repeated, so that hands, fingers, etc. There is a risk of it getting caught in the gap.

The present invention aims to solve the above-mentioned conventional problems, and will be described in detail below based on examples.

(Means for solving the problem) Reference numeral 1 denotes a drive shaft connected to a lifting mechanism for a floor such as a bed, and this drive shaft 1 is the screw shaft itself that constitutes the lifting mechanism, as well as an appropriate rotating shaft. It may also be a rotating shaft connected via a force transmission mechanism.
An actuating rod 2 is bendably connected to the end of the drive shaft 1, and a driving cylinder 4 constituting a crank handle portion 3 is fitted into the actuating rod 2.
The operating rod 2 is provided with a fixed insert 5 at its end and a movable insert 6 movable and rotatable with respect to the operating rod 2. The fixed fitting insert 5 is configured to be fitted into the drive cylinder 4 so as to be movable and rotatable in the axial direction, and the movable fitting insert 6
A convex portion 8 is formed in the axial groove 7 formed in the drive cylinder 4.
The structure is such that the drive cylinder 4 can be moved only in the axial direction by engaging with the drive cylinder 4. Further, the opposing surfaces of the fixed insert 5 and the movable insert 6 are configured as clutch surfaces 9, 9' which can freely rotate due to excessive load, and between the drive cylinder 4 and the movable insert 6, the A spring 10 is provided which biases the insert in the direction of the fixed insert 5.
the clutch surface 9, which is free to idle due to excessive load;
9' may be configured as a single engaging inclined surface as in the embodiments shown in FIGS. It may be constructed as a meshing clutch surface, such as a cross-section, or may be constructed as a friction surface depending on the case. Note that reference numeral 11 is a connecting member that bendably connects the actuating rod 2 to the end of the drive shaft 1, but the actuating rod 2 may be connected to the drive shaft 1 in any appropriate manner, and the washer 12, etc. You can configure it as follows. Furthermore, the structure of the crank handle portion 3 is also suitable.

(Function) In the above configuration, when the drive shaft 1 and the actuating rod 2 are arranged on the same axis without being bent, the drive cylinder 4 is urged in the direction of the drive shaft 1 by the spring force of the spring 10. The distal end portion 13 maintains the coaxial line state. Further, the movable insert 6 is also urged by the spring force of the spring 10, and its drive inclined surface 9' is pressed against the drive inclined surface 9 of the fixed insert 5. The end of the drive cylinder 4 may have a notch 14 formed on the bending direction side of the actuating rod 2 as shown in FIGS. 1 to 3 to facilitate the bending described later. As shown in FIG. 4b, it may be configured in a cylindrical shape without a notch so that the coaxial line state can be more securely maintained.

When the drive cylinder 4 is rotated with the grip 15 in this state, the rotational force is first transmitted from the groove 7 to the movable insert 6 via the convex portion 8. The rotational force of the movable insert 6 is then transmitted to the fixed insert 5 via the clutch faces 9, 9', and thus can drive the drive shaft 1 in rotation via the actuating rod 2.

However, if the drive shaft 1 becomes unable to rotate when the floor or the like reaches its limit of elevation, if you attempt to further rotate the drive cylinder 4 without noticing this, the actuating rod 2 Since it cannot rotate, an excessive torque is applied to the drive cylinder 4. However, in the present invention, the facing surfaces of the fixed insert 5 and the movable insert 6 are replaced by a clutch surface 9, which can freely rotate due to excessive load.
9', and since the drive cylinder 4 is rotatable relative to the fixed insert 5, the spring 10
When a torque exceeding a predetermined torque, which can be set by the pressure contact force of the clutch surfaces 9, 9' and the shape of the clutch surfaces 9, 9, is applied, the movable insert 6 is fixedly engaged as shown in FIG. It rotates idly while moving forward and backward with respect to the insert 5, so that no excessive torque is applied to the drive cylinder 4.

The fixed insert 5 and the movable insert 6, which constitute the clutch surfaces 9 and 9' that can freely rotate due to excessive load, are completely internally contained within the drive cylinder 4, so they are There is absolutely no chance of your hands or fingers getting caught when you are idling.

Next, when the actuating rod 2 is bent, the spring 10
The drive barrel 4 is urged in the direction of the drive shaft 1 by the spring force, and a proper position of the drive barrel 4 comes into pressure contact with the connecting member 11 or the side of the drive shaft 1, so that the bent state is maintained. Incidentally, the bending operation of the actuating rod 2 can be performed in one-touch by forming a notch 14 on the bending direction side as in the configurations shown in FIGS. 1 to 3. As in the configuration shown in FIG. 4b, the drive cylinder 4 may be retracted from the drive shaft 1 first and then bent.

(Effects of the invention) As described above, the crank handle device of the invention has the following features:
When a torque exceeding a predetermined level is applied to the drive cylinder that makes up the crank handle part, it can idle, so that excessive torque is not applied, thus preventing damage to the members making up the lifting mechanism and injury to the operator. It also has the effect that it does not get in the way by being bent and stored when not in use. In particular, the present invention completely houses the fixed insert and the movable insert, which constitute the clutch surface that can freely rotate under excessive load, within the drive cylinder, compared to the conventional method in which these were placed outside. Like the ones in
There is no chance of getting your hands or fingers caught during idling, resulting in a high level of safety. In addition, the present invention has a structure in which the spring for setting the predetermined torque and the spring for holding the crank handle part in the operating state and the retracted state are used, so the number of parts is reduced and the structure is simplified. This has the effect of making it easier to manufacture and reducing costs.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which a is an explanatory cross-sectional view in a state of use, b is a perspective view partially illustrative of the constituent members, and c and d are a, respectively. 2 is an explanatory sectional view of the idling state, FIG. 3 is an explanatory sectional view of the refracted state, and FIGS. 4a and 4b are explanations of other embodiments, respectively. FIG. Furthermore, FIGS. 5a and 5b are an explanatory cross-sectional view and a side view, respectively, showing the configuration and usage condition of a conventional example. Code 1... Drive shaft, 2... Operating rod, 3... Crank handle part, 4... Drive cylinder, 5... Fixed insert, 6... Movable insert, 7... Groove, 8... Convex Department,
9, 9'...Clutch surface, 10...Spring, 11...
...Connecting member, 12... Washer, 13... Tip, 14... Notch, 15... Grip.

Claims (1)

[Scope of utility model registration request] An operating rod is bendably connected to the end of a drive shaft connected to a lifting mechanism for the floor of a bed, etc., and a drive cylinder constituting a crank handle portion is fitted into the operating rod. is provided with a fixed insert at the end and a movable insert that is movable and rotatable with respect to the actuating rod, and the fixed insert is movable and rotatable in the axial direction with respect to the drive cylinder. In addition, the movable insert is configured to engage a convex portion in an axial groove formed in the drive cylinder so that it is movable only in the axial direction with respect to the drive cylinder, The facing surfaces of the fixed insert and the movable insert are constructed as clutch surfaces that can freely rotate under excessive load, and the movable insert is arranged between the drive cylinder and the movable insert in the direction of the fixed insert. A crank handle device for raising and lowering a floor of a bed, etc., characterized by being provided with a biasing spring.